The present invention relates to an apparatus for facilitating the delivery of a child during childbirth, and more specifically relates to vacuum extractors for use during childbirth.
During childbirth, the birth mother is sometimes unable to deliver the child without assistance. In some cases, all that is required is for a nurse, midwife, or attending physician to push down on the birth mother""s upper abdomen when she bears down during delivery. In other cases, it is necessary for a physician to perform a cesarean section. For those cases in between the two extremes, some sort of intermediate assistance is often required. Such intermediate assistance generally entails the use of some sort of device to aid in the delivery of the child. These devices may likewise be required to assist a physician during particularly difficult cesarean sections.
One example of such a device is forceps. Forceps, however, tend to be bulky and difficult to operate. In addition, the use of forceps, at the very least, is uncomfortable for the mother and child and risks injury to both.
An alternative device to forceps is a vacuum extractor device, like the one described in U.S. Pat. No. 3,202,152. Such a device comprises a cup, which is placed onto the child""s head. The device further comprises an elongated hollow stem, which is used to position the cup onto the child""s head and through which vacuum pressure is introduced into the cup. The introduction of vacuum pressure into the cup results in suction between the cup and the child""s head. The resultant suction is then used to extract the child from the birth canal by pulling in an appropriate direction on some sort of gripping device coupled to the vacuum extractor. A similar device is manufactured and sold by Prism Enterprises, Inc. of San Antonio, Tex.
Although vacuum extractor devices, like the one manufactured and sold by PrisTech, are widely used, the relatively flexible edge of the cup, which facilitates the formation of a good seal between the cup and the child""s head, could, due to its relative thinness, abrade or injure the child or mother. U.S. Pat. Nos. 5,163,944 and 5,281,229 disclose vacuum extractors which attempted to address this potential problem, by lining the cup with a second cup formed of a soft, pliable material, which, when assembled, wraps around the edge of the cup. Thus, the first cup provided the relatively rigid structure of the extractor cup while the second cup provided a soft, relatively friendly contact with the child""s head. While this vacuum extractor design reduced the possibility abrasion or injury to maternal tissues and the child by cushioning the contact between the vacuum extractor cup and the adjacent tissue, the design was not without its disadvantages. Given that the soft material from which the liner is formed is opaque, the liner occludes vision through the cup. Accordingly, the liner may make it difficult to visually determine if the cup is properly positioned on the child""s head or to visually monitor the fetal tissue during delivery to ensure that the amount of suction is appropriate. In addition, if the vacuum extractor is not used properly, the liner may roll off the edge of the cup.
The present invention seeks to overcome the problems of the prior art. Accordingly, it is an object of the present invention to provide a vacuum extractor, which offers the advantages attendant an extractor having a liner, without compromising visibility through the cup and without risking the liner rolling off the edge of the cup. Another object of the present invention is to provide a softer contact between the extractor and child. These and other objects and advantages of the present invention will become apparent from the disclosure herein.
The present invention provides an obstetrical vacuum extractor comprising a vacuum cup, which is substantially in the shape of a bell with an outwardly flaring edge and a basal opening. A hollow stem adapted for connecting with a vacuum source communicates with the inner cavity and basal opening of the cup. The cup is also provided with at least one handle to facilitate maneuvering of the cup during delivery. In accordance with the invention, the extractor further comprises a secondary lip, which is molded from a relatively soft elastomeric material, and is secured on the outwardly flaring edge of the vacuum cup. The relatively soft lip presents a friendly edge to the maternal and fetal tissue as the cup is positioned and during delivery. Further, because the relatively soft second material is disposed only along the edge of the cup, the physician can better observe the interaction between the cup and the child""s head. Accordingly, the physician can readily observe whether the cup is properly positioned and if the level of suction is appropriate.
Preferably, the edge of the vacuum cup adjacent the basal opening includes a structure which enhances the attachment of the molded lip. While various designs may be appropriate, the vacuum cup may include one or more protrusions, such as annular ridges, which extend about the periphery of the outwardly flaring edge of the cup. The ridges provide additional gripping surfaces for the softer material of the secondary molded lip.
Alternately, the flaring edge of the cup may be provided with one or more bores which extend through the edge of the cup. The bores are disposed about the periphery of the flaring edge, preferably at substantially regular intervals. When the secondary lip is molded to the flaring edge of the cup, the elastomeric material flows into the bores and along both the inner and outer surfaces of the flaring edge of the cup to secure the secondary lip to the cup.